Optical image stabilization actuator driver power distribution control
View Patent ↗Various embodiments provide an optical image stabilization circuit including a drive circuit having a power waveform generator and a power waveform conversion circuit. The power waveform generator generates a power waveform. The power waveform conversion circuit converts the power waveform to a power drive signal. An actuator is then driven by the power drive signal to move a lens accordingly and compensate for any movements and vibrations of a housing of the lens.
1. A device, comprising:
a lens;
an actuator configured to move the lens;
a position sensor configured to measure a position of the lens;
a gyroscope configured to measure movement of the device;
a controller configured to determine drive signal data based on the position of the lens and the movement of the device;
a power waveform generator configured to generate a power waveform based on the drive signal data, the power waveform having a calculated minimum non-zero amplitude value, a calculated maximum non-zero amplitude value, and a calculated intermediate non-zero amplitude value; and
a power waveform conversion circuit including:
a digital to analog converter configured to convert the power waveform into a voltage signal having amplitude values corresponding to the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, and the calculated intermediate non-zero amplitude value;
a voltage to current converter circuit configured to apply a gain to the voltage signal, and convert the voltage signal to an electric current signal; and
a driver circuit configured to drive the actuator with the electric current signal to move the lens.
2. The device of claim 1 wherein the voltage to current converter circuit includes:
an amplifier including a first input, a second input, and an output, the first input electrically coupled to the digital to analog converter;
a resistor electrically coupled to the second input of the amplifier and ground;
a first capacitor electrically to the second input of the amplifier and ground;
a first transistor electrically coupled to the output of the amplifier;
a second transistor electrically coupled to the first transistor;
a third transistor electrically coupled to the second transistor and the driver circuit; and
a second capacitor electrically coupled to the second transistor and the third transistor.
3. The device of claim 1 wherein the driver circuit is an H bridge circuit.
4. The device of claim 1 wherein the power waveform generator is configured to calculate durations of the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, and the calculated intermediate non-zero amplitude value based on the drive signal data.
5. The device of claim 4 wherein a duration of one of the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, or the calculated intermediate non-zero amplitude value is twice as long as a duration of another one of the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, or the calculated intermediate non-zero amplitude value.
6. The device of claim 1 wherein the power waveform is a multi-cycle power waveform that includes the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, and the calculated intermediate non-zero amplitude value in each cycle.
7. The device of claim 1 wherein the drive signal data includes a power input parameter that sets a total power value for the power waveform.
8. The device of claim 1 wherein the drive signal data includes a transition limit parameter that sets a maximum amount of change in amplitude between one time interval to a subsequent time interval for the power waveform.
9. A device, comprising:
a power waveform generator configured to receive drive signal data, and generate a power waveform based on the drive signal data, the power waveform having a calculated minimum non-zero amplitude value, a calculated maximum non-zero amplitude value, and a calculated intermediate non-zero amplitude value; and
a power waveform conversion circuit, including:
a digital to analog converter configured to convert the power waveform into a voltage signal;
a voltage to current converter circuit configured to apply a gain to the voltage signal, and convert the voltage signal to an electric current signal; and
a driver circuit configured to output the electric current signal.
10. The device of claim 9 wherein the voltage to current converter circuit includes:
an amplifier including a first input, a second input, and an output, the first input electrically coupled to the digital to analog converter;
a resistor electrically coupled to the second input of the amplifier and ground;
a first capacitor electrically to the second input of the amplifier and ground;
a first transistor electrically coupled to the output of the amplifier;
a second transistor electrically coupled to the first transistor;
a third transistor electrically coupled to the second transistor and the driver circuit; and
a second capacitor electrically coupled to the second transistor and the third transistor.
11. The device of claim 9 wherein the driver circuit is an H bridge circuit.
12. The device of claim 9 wherein the power waveform generator is configured to calculate durations of the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, and the calculated intermediate non-zero amplitude value based on the drive signal data.
13. The device of claim 9 wherein the power waveform is a multi-cycle power waveform that includes the calculated minimum non-zero amplitude value, the calculated maximum non-zero amplitude value, and the calculated intermediate non-zero amplitude value in each cycle.
14. The device of claim 9 wherein the drive signal data includes a power input parameter that sets a total power value for the power waveform.
15. The device of claim 9 wherein the drive signal data includes a transition limit parameter that sets a maximum amount of change in amplitude between one time interval to a subsequent time interval for the power waveform.
16. A device, comprising:
an actuator;
a power waveform generator configured to receive drive signal data, and generate a power waveform based on the drive signal data, the power waveform including a plurality of cycles, the power waveform having a calculated minimum non-zero amplitude value, a calculated maximum non-zero amplitude value, and a calculated intermediate non-zero amplitude value in each of the plurality of cycles;
a power waveform conversion circuit including:
a digital to analog converter configured to convert the power waveform into a voltage signal;
a voltage to current converter circuit configured to apply a gain to the voltage signal, and convert the voltage signal to an electric current signal; and
a driver circuit configured to drive the actuator with the electric current signal to move a lens.
17. The device of claim 16 wherein the voltage to current converter circuit includes:
an amplifier including a first input, a second input, and an output, the first input electrically coupled to the digital to analog converter;
a resistor electrically coupled to the second input of the amplifier and ground;
a first capacitor electrically to the second input of the amplifier and ground;
a first transistor electrically coupled to the output of the amplifier;
a second transistor electrically coupled to the first transistor;
a third transistor electrically coupled to the second transistor and the driver circuit; and
a second capacitor electrically coupled to the second transistor and the third transistor.
18. The device of claim 16 wherein the driver circuit is an H bridge circuit.
19. The device of claim 16 wherein the drive signal data includes a power input parameter that sets a total power value for the power waveform.
20. The device of claim 16 wherein the drive signal data includes a transition limit parameter that sets a maximum amount of change in amplitude between one time interval to a subsequent time interval for the power waveform.